Share trading on the London Stock Exchange was suspended all morning because
of an as yet undiagnosed problem with the exchange’s prices data.

The LSE Group, the company behind the stock exchange, has described this morning’s events as a “glitch”. But it’s more than that.

This company saw its Italian stock exchange operation close earlier in the week because of technology problems (although it was this morning keen to blame that debacle on a third party supplier ). And the LSE has other recent form, having had to cease trading in 2008.

LSE went live last Monday with a new technology platform called Millennium and insists that it has complete confidence in its kit. I’m not sure how it can claim that given this week’s events. The fact they are unrelated is no reassurance – quite the opposite, suggesting there may be numerous separate issues that need addressing.

Xavier Rolet, the company’s chief executive, is keeping his powder dry until his IT geeks have worked out what on earth is going on. But once he has an answer we deserve an explanation.

This is not just damaging to Rolet’s company and its reputation, handing a simple advantage to its rivals. It also makes a laughing stock of London as the world’s leading financial centre.

Earlier this month Rolet announced the LSE’s acquisition of the Toronto stock exchange. Very impressive. But what would be more impressive is if we could trade shares on our own stock exchange here in London.